[STM32] Deploy SPI_ASYNCH to all family

the SPI_ASYNCH feature has been already activated for STM32F4.
This patchset makes it supported on all STM32 families by:
- moving spi_s structure at family level instead of board level
- using the F4 spi_api.c reference implementation and making it a common
stm_spi_api.c file which makes maintenance a lot easier.
- the only part that needs to be implemented for each family is the computation
of the clock frequency input to the spi peripheral which is not the same
accross families. So this is what remains in the spi_api.c of each family.

Because of the introduction of the common file, all the above modifications
needs to be done at once.

Author: Laurent MEUNIER

targets/TARGET_STM/TARGET_STM32F0/TARGET_DISCO_F051R8/objects.h

@@ -66,20 +66,6 @@ struct dac_s {
     uint32_t channel;
 };
 
-struct spi_s {
-    SPIName spi;
-    uint32_t bits;
-    uint32_t cpol;
-    uint32_t cpha;
-    uint32_t mode;
-    uint32_t nss;
-    uint32_t br_presc;
-    PinName pin_miso;
-    PinName pin_mosi;
-    PinName pin_sclk;
-    PinName pin_ssel;
-};
-
 struct i2c_s {
     I2CName  i2c;
 };

targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F030R8/objects.h

@@ -60,20 +60,6 @@ struct analogin_s {
     uint32_t channel;
 };
 
-struct spi_s {
-    SPIName spi;
-    uint32_t bits;
-    uint32_t cpol;
-    uint32_t cpha;
-    uint32_t mode;
-    uint32_t nss;
-    uint32_t br_presc;
-    PinName pin_miso;
-    PinName pin_mosi;
-    PinName pin_sclk;
-    PinName pin_ssel;
-};
-
 struct i2c_s {
     I2CName  i2c;
 };

targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F031K6/objects.h

@@ -60,20 +60,6 @@ struct analogin_s {
     uint32_t channel;
 };
 
-struct spi_s {
-    SPIName spi;
-    uint32_t bits;
-    uint32_t cpol;
-    uint32_t cpha;
-    uint32_t mode;
-    uint32_t nss;
-    uint32_t br_presc;
-    PinName pin_miso;
-    PinName pin_mosi;
-    PinName pin_sclk;
-    PinName pin_ssel;
-};
-
 struct i2c_s {
     I2CName  i2c;
 };

targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F042K6/objects.h

@@ -60,20 +60,6 @@ struct analogin_s {
     uint32_t channel;
 };
 
-struct spi_s {
-    SPIName spi;
-    uint32_t bits;
-    uint32_t cpol;
-    uint32_t cpha;
-    uint32_t mode;
-    uint32_t nss;
-    uint32_t br_presc;
-    PinName pin_miso;
-    PinName pin_mosi;
-    PinName pin_sclk;
-    PinName pin_ssel;
-};
-
 struct i2c_s {
     I2CName  i2c;
 };

targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/objects.h

@@ -60,20 +60,6 @@ struct analogin_s {
     uint32_t channel;
 };
 
-struct spi_s {
-    SPIName spi;
-    uint32_t bits;
-    uint32_t cpol;
-    uint32_t cpha;
-    uint32_t mode;
-    uint32_t nss;
-    uint32_t br_presc;
-    PinName pin_miso;
-    PinName pin_mosi;
-    PinName pin_sclk;
-    PinName pin_ssel;
-};
-
 struct i2c_s {
     I2CName  i2c;
 };

targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/objects.h

@@ -66,20 +66,6 @@ struct dac_s {
     uint32_t channel;
 };
 
-struct spi_s {
-    SPIName spi;
-    uint32_t bits;
-    uint32_t cpol;
-    uint32_t cpha;
-    uint32_t mode;
-    uint32_t nss;
-    uint32_t br_presc;
-    PinName pin_miso;
-    PinName pin_mosi;
-    PinName pin_sclk;
-    PinName pin_ssel;
-};
-
 struct i2c_s {
     I2CName  i2c;
 };

targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F091RC/objects.h

@@ -66,20 +66,6 @@ struct dac_s {
     uint32_t channel;
 };
 
-struct spi_s {
-    SPIName spi;
-    uint32_t bits;
-    uint32_t cpol;
-    uint32_t cpha;
-    uint32_t mode;
-    uint32_t nss;
-    uint32_t br_presc;
-    PinName pin_miso;
-    PinName pin_mosi;
-    PinName pin_sclk;
-    PinName pin_ssel;
-};
-
 struct i2c_s {
     I2CName  i2c;
 };

targets/TARGET_STM/TARGET_STM32F0/common_objects.h

@@ -49,6 +49,21 @@ struct pwmout_s {
     uint8_t inverted;
 };
 
+struct spi_s {
+    SPI_HandleTypeDef handle;
+    IRQn_Type spiIRQ;
+    SPIName spi;
+    PinName pin_miso;
+    PinName pin_mosi;
+    PinName pin_sclk;
+    PinName pin_ssel;
+#ifdef DEVICE_SPI_ASYNCH
+    uint32_t event;
+    uint8_t module;
+    uint8_t transfer_type;
+#endif
+};
+
 struct serial_s {
     UARTName uart;
     int index; // Used by irq